Differential pump.



Patented Dec. I7, IQIJI.

E. M. CORYELL. DIFFERENTIAL PumP.

Application filed Aug. 20, 1901.,

(No Model.)

THE norms PETERS coy. Pnofoumou wishmgn'ow, u 'c Miran @ra'rns ATlENT lfltlfit EDWIN M. CORYELL, OF NElV YORK, N. Y., ASSIGNOR TO JULIA E.CAMERON, OF NEWV YORK, N. Y., PROPRIETRESS OF THE A. S. CAMERON STEAMPUMP WORKS.

DlFll-"ERENTIAL PUP.

SPEGIFIGATION forming part of Letters Patent No. 689,065, dated December17, 1901.

Application filed August 20, 1901- Serial No. 72,674. (No model.)

To (tZZ whom it may concern.-

Be it known that I, EDWIN M. OoRYnLL, of the city and State of New York,have invented a new and useful Differential Pump, which is fully setforth in the following specification.

My invention relates in particular to sinking-pumps for mines, dcc. butmay be applied to other types. It is a differential pump in which by theupstroke a shell is lifted, raising a certain amount of water fordischarge, and on the downstroke a plunger forces out and discharges alike quantity, whereby a uniform flow of the discharge is kept up. Theplunger is hollow and constitutes the airchamber. For convenience Ishall illustrate and explain an embodiment applied to a verticalsinking-pump in which the terms upper andlower are of course relative.

The drawing annexed shows a vertical section of a vertical sinking-pump.

The water-cylinder of this pump comprises the lower section A, the uppersection B, and the plug 0, secured together, as by their flanges, (inthe manner shown,) and holding the annular packings a and b. Thecylinder is of substantially uniform diameter throughout and carries thesuction-valve D at its lower end. The upper end is reduced to inclosethe reduced plunger and at the upper end is located the discharge-outletB. The steam-pump, &c., atE is connected to the water-cylinder bypillars e e.

The pump-rodfactuates the hollow plunger F with the enlarged open-endedshell G, whose lower end is closed by the lifting-valve D. PlungerF isclosed at the upper end, as shown, and is secured to shell G bytransverse ribs 9 g, there being thus free communication from theinterior of both the plunger and the shell into the discharge-outlet B.The portion of the plunger that descends into the cylinder is ofapproximately the same height as the shell above its valve, but is ofonly one-half its area in cross-section, so that the cubic displacementof the plunger is one-half the contents of the shell.

Assuming now that the plunger is at the bottom of its stroke, on theupstroke the suction tends to produce a vacuum in the lower portion,(within section A,) whereupon suction-valve D is raised and Water enterssection A. Upon the succeeding downstroke valve D is closed, valve D isopened, and (disregarding plunger F for the moment) the shell Grdescends, surrounding and becoming filled with the water now in sectionA. On the next upstroke valve D, being now closed, raises this water,and within a few strokes upon every rise of shell G a quantity of waterequal to the contents of the shell will be forced out at discharge B;but hollow plunger F at every downstroke displaces its own volume inwater, and its volume being just half the contents of the shell itaccordingly displaces through outlet B one-half the quantity justpreviously brought up by shell G. Consequently the latter on its nextupstroke will have just half the quantity to discharge in other words,the same quantity of water is discharged both on the upstroke and on thedownstroke, a uniform fiow being thus ob tained. The function of theair-chamber contained in the plunger F is obvious.

Of course I do not limit myself to the precise arrangement andconstruction just described, as changes may be made in either Withoutdeparting from the spirit of my invention. For example, instead ofmaking the hollow plunger of one-half the cross-sectional area and ofthe same available length as the shell its length and cross-section maybe varied inversely, so long as its available displacement remainsapproximately half the Volume of the shell.

Having thus described my invention, I claim- In a pump, the combinationwith a pumpcylinder having a suction-valve at its bottom and a dischargeat its upper end, of a differential plunger consisting of a hollow upperportion closed at top and open at bottom and an open-ended shellconstituting the lower portion and closed at its bottom byaliftingvalve, said two portions being connected together by means ofribs located interiorly of said portions so as to permit freecommunication between their interiors and the pump cylinder, and theavailable displacement of said upper portion being substantially onehalf the volume contained within said shell.

In testimony whereof I have signed this specification in the presence oftwo subscrib ing witnesses.

EDWIN M. CORYELL.

Witnesses:

G. A. L. MASSIE, ELISHA K. CAMP.

